Annie Ross's voice has a kind of dreamy watchfulness that is a definition of 1950s hip. This four-album, double-CD collection from her jazz heyday finds her in the company of a host of star players, including Stan Getz, Zoot Sims and Gerry Mulligan. Drop in on any of the 48 tracks and you will encounter immaculate jazz singing. But the purest distillation of a style which Kenneth Tynan described as that of a fallen angel comes from two modest sessions recorded in London in 1956. The coolest thing since cucumbers, as they used to say.